KEY WEST, Florida (CNN) -- The USNS General Hoyt S. Vandenberg, a retired U.S. Navy warship, embarked on a sedentary new career Wednesday on the floor of the Gulf of Mexico.

The USNS Vandenberg was intentionally sunk Wednesday to create an artificial reef for marine life.

The decommissioned warship was scuttled in the Florida Keys National Marine Sanctuary between 10:20 a.m. and 10:30 a.m. ET to become the world's second-largest artificial coral reef.

The 17,250-ton ship sank in less than two minutes, said Andy Newman, spokesman for the Florida Keys Tourism Council. It is resting about 140 feet below the surface, but much of its bulk is only 40 to 70 feet below the surface.

"It went down like a rock," he told CNN. "Everything looked very, very smooth."

About 300 boats positioned themselves as close as possible to the site, and cheers went up when the Vandenberg slipped beneath the water seven miles south of Key West, the spokesman said. Watch the Vandenberg sink »

Newman, who was circling in a helicopter above the 522-foot-long ship, said the Vandenberg appeared to rest in a level position on the Gulf floor. Divers were to assess its position Wednesday. Authorities said once final assessments of the ship are made, divers can begin exploring.

The goal of the $8.6 million project is to divert fishing and diving pressure away from natural reefs, according to the Florida Fish and Wildlife Conservation Commission.

Don't Miss

The commission "estimates that the vessel's life span of at least 100 years will contribute stable, long-term habitat for scores of marine fish species, and provide exceptional diving and fishing opportunities for Florida residents and visitors," its Web site says.

To sink the Vandenberg, holes were made above the waterline in the side of the ship and throughout various decks, Newman said. Explosive charges were embedded in the bilge area below the water. The explosives detonated inside the hull, blowing outward.

The National Oceanic and Atmospheric Administration projects that the Vandenberg artificial reef will result in an annual increase of about $7.5 million in expenditures in the economy of Monroe County, which includes Key West.

Sinkthevandenberg.com -- a joint effort by Artificial Reefs of the Keys and Valeo Films -- had offered a live, online stream of the event, but the system apparently was overloaded, making the site inaccessible.

The Vandenberg was built at the Kaiser shipyard in Richmond, California, in 1943. It was commissioned as a World War II troop transport ship. After Japan surrendered, the Vandenberg was the first Navy ship to return to New York Harbor.

During the 1950s the ship was used to transport refugees from Europe and Australia to America. In the 1960s the Air Force used the Vandenberg to track missiles. It also was used to track rockets and early space shuttle launches.

The ship was decommissioned in 1986 and was anchored with more than 25 other mothballed ships in Norfolk, Virginia. The Vandenberg was towed to Key West last month.

The Vandenberg was chosen from among 400 decommissioned military vessels mainly based on appearance: "her topside structure, her smooth, interesting hull lines, big girth and her starring role in a motion picture," Newman said.

The ship was featured in the 1999 movie "Virus," starring Donald Sutherland and Jamie Lee Curtis.

Four men who had served on the Vandenberg traveled to Key West to see the ship go to its final resting place.

Patrick Utecht worked for more than 20 years as a civilian contractor on the Vandenberg when it was used for missile and radar tracking and data collection.

When he heard about its future as part of an artificial reef, Utecht said, "My feeling was one of elation."

"I can say that many of us [crew members] were thrilled that where she was going, she would keep her name and place in history."

"I think it's a far better use of her than being cut up," he added.

The largest ship ever scuttled to create an artificial reef was the decommissioned aircraft carrier USS Oriskany, which sank to the bottom of the Gulf of Mexico off the Florida coast in 2006, according to the U.S. Navy. The former warship slipped under the water about 24 miles south of Pensacola, Florida, the Navy says on its Web site.

The Oriskany was 888 feet long, and weighed 32,000 tons. It sank in water about 212 feet deep.